Jackson, who finished with 12 points, hit a jumper with 3:46 remaining in the game that gave her 536 points — one more than former Brazil star Janeth Arcain.
The four-time Olympian's record-breaking basket gave Australia a comfortable 13-point lead. Liz Cambage scored 17 points for the Australians. Ma Zengyu led China with 15 points.
Australia and the United States have met in three straight Olympic finals, with the Americans winning the gold each time. Australia failed to win its group and will now have to play the favoured Americans one round earlier.